Enable interrupts. Cycle through all the patterns.

Author: InPermutation

main.s

@@ -7,6 +7,16 @@
   .include 'monitor.s'
 
 irq:
+  pha
+
+  lda VDP_REG ; read VDP status to clear 'F', the interrupt flag.
+
+  vdp_write_vram (VDP_NAME_TABLE_BASE + VDP_COLS + 1)
+
+  pla
+  sta VDP_VRAM
+  inc
+
   rti
 
 reset:

vdp.s

@@ -116,7 +116,7 @@ vdp_enable_display:
 
 vdp_register_inits:
 vdp_register_0: .byte %00000000 ; 0  0  0  0  0  0  M3 EXTVDP
-vdp_register_1: .byte %10010000 ;16k Bl IE M1 M2 0 Siz MAG
+vdp_register_1: .byte %10110000 ;16k Bl IE M1 M2 0 Siz MAG
 vdp_register_2: .byte $00       ; Name table base / $400. $00 = $0000
 vdp_register_3: .byte $00       ; Color table base (currently unused)
 vdp_register_4: .byte $01       ; Pattern table base / $800. $01 = $0800